code: def is_valid_metadata_key(text):
      """Can this text be a proper key?"""
      return bool(_IS_VALID_METADATA_KEY.match(text))
  
imports: import ast
  import re
  from json import dumps, loads
  from .languages import _JUPYTER_LANGUAGES
label_desc: Use image node_id 11 for calling a global function with example usage: is_valid_metadata_key(text) and returns: bool